Method of manufacturing highly viscous,acidic base materials for detergents

ABSTRACT

METHOD OF MANUFACTURING HIGHLY VISCOUS, ACIDIC BASE MATERIALS FOR DETERGENTS BY CONVERTING SILICA HYDROGEL OR SILICA ALUMINA HYDROGEL INTO A HYDROSOL WITH WATER BY THE TECHNIQUE OF WET GRINDING, AND CONTACTING THE THUS OBTAINED HYDROSOL WITH MINERAL ACID, THEREBY REGULATING THE MINERAL ACID CONTENT OF SAID HYDROSOL TO FROM 3 TO 20% BY WEIGHT.

United States Patent 3,709,823 METHOD OF MANUFACTURING HIGHLY VISCOUS, ACIDIC BASE MATERIALS FQR DETERGENTS Yujiro Sugahara, Tokyo, and Masanori Tanaka, Shibata, Japan, assignors to Mizusawa Industriai Chemicals, Ltd., Osaka, Japan No Drawing. Filed June 16, 1970, Ser. No. 46,837 Int. Cl. B013 13/00; (311d 3/08 US. Cl. 252-136 4 Claims ABSTRACT OF THE DISCLOSURE Method of manufacturing highly viscous, acidic base materials for detergents by converting silica hydrogel or silica alumina hydrogel into a hydrosol with water by the technique of wet grinding, and contacting the thus obtained hydrosol with mineral acid, thereby regulating the mineral acid content of said hydrosol to from 3 to 20% by Weight.

BACKGROUND OF THE INVENTION (a) Field of the invention The present invention relates to a method of manufacturing a strong acidic silica sol to be used as detergent base materials and more particularly to a method of manufacturing a highly viscous and strongly acidic silica sol by the use of silica hydrogel or silica alumina hydrogel as raw materials.

(b) Description of the prior art It has been said that there are two important requisites in the use of silica sol as a detergent base material, namely, (1) it must exhibit a high viscosity under a strongly acidic medium of and (2) it must too be capable of maintaining a high viscosity, even if the content of silica is small. However, under existing circumstances, it is impossible to prepare silica sol satisfying the aforesaid two serious important requisites at the same time by the conventional methods of manufacturing silica sol. The conventional methods of manufacturing silica sol include using a silica xerogel prepared by the vapour phase process, for instance Aerosil, and hydrochloric acid etc. However, the silica sol obtained by this method, generally lacks a sufiicient viscosity under a strongly acidic medium and the content of silica must be exceedingly increased in order to increase this viscosity.

SUMMARY OF THE INVENTION The inventors have carried on studies to obtain silica sol which satisfies the above-described two important requisites simultaneously. It has been discovered that when silica hydrogel is subjected to wet grinding into fine particles, thereby being changed into the state of a hydrosol, and this sol is contacted with strong mineral acids such as hydrochloric acid, sulfuric acid and nitric acid, the silica hydrosol contains a large amount of strong acid, as the result of which there is obtained a highly viscous silica sol. When the usual silica gel prepared by the vapour phase process is dispersed in water, in an amount of 2.2 wt. percent of silica and 9.0 wt. percent of hydrochloric acid, the coeflicient of viscosity of the dispersed liquid is 120 cp. measured by a Brookfield viscometer. However, when silica hydrogel is subjected to wet grinding with water, the silica content of the resulting silica hydrosol is 6 wt. percent, and the coefiicient of viscosity of this silica hydrosol is 40 cp. It, furthermore, has been found that when concentrated hydrochloric acid and fresh water or diluted hydrochloric acid is added to the silica hydrosol so that the silica concentration thereof 3,709,823 Patented Jan. 9, 1973 ice is 2.2 wt. percent and the hydrochloric acid concentration is 9.0 wt. percent, the coefficient of viscosity of the silica h'ydrosol increases up to a high value of 410 cp.

The inventors have carried on further experiments and have discovered that when silica hydrogel is mixed with hydrochloric acid so that the concentration of silica is 2.2 wt. percent and the concentration of hydrochloric acid is 9.0 wt. percent and the thus obtained substance is subjected to wet grinding, the coetficient of viscosity thereof is 290 cp., whilst that of a substance prepared from a xerogel in the same manner is 15 cp.

Furthermore, the tendency as described above has been observed in respect of the viscosity changes when the silica concentration is in the range of from 0.5 wt. percent to 5.0 Wt. percent. Still further, the same tendency has been also observed with regard to the viscosity changes when the hydrochloric acid concentration is in the range of from 3 to 20 wt. percent.

As is clear from above-mentioned three experimental examples, the substances prepared by the use of silica hydrogel all demonstrate a high coeificient of viscosity compared with those prepared by Xerogels. The substance prepared by first wet grinding hydrogel with water and then adding hydrochloric acid thereto demonstrates the highest coefficient of viscosity.

Referring now to the grinding conditions in these examples, when silica hydrogel or silica alumina hydrogel is subjected to wet grinding with water, while holding the pH value at 7, the material being ground has a high coefiicient of viscosity, so that the concentration of silica in the material capable of being ground is less than 3 wt. percent. When the pH value is held at 3, the concentration of silica in the material capable of being ground is 6 wt. percent, and furthermore when the pH value is held at from 1 to 2, the said silica concentration can be made 8 Wt. percent.

The above-mentioned facts boil down to this, i.e., that the choice of pH at the time of wet grinding makes it possible to increase or decrease the concentration of silica during the time when wet grinding is being conducted. This is an important matter in respect of making efiicient use of the grinder when wet grinding is carried out.

Further, when the pH value of the material being ground is made less than 1 by increasing the concentration of strong acid and adding an amount without measuring the pH, for instance more than 2 wt. percent of hydrochloric acid, the coefficient of viscosity of the material being ground increases and it is difiicult to raise the silica concentration.

As described above, whichever Way the silica sol substance may be made, wherein silica hydrogel and silica alumina hydrogel are subjected to wet grinding with water or strong acid, there can be produced a fine silica sol containing a large amount of strong acid as compared with that obtained by using a silica gel prepared by the vapour phase process.

When salts, for instance various kinds of metallic salts such as NaCl, KCl, CaCI MgCl AlCl etc., are incorporated in the strong acid silica sol solution thus obtained, the coeflicient of viscosity increases. When there is further added a surface active agent, for instance a cation surface activator such as a quaternary ammonium salt, etc., this sticky liquid, exhibits the characteristics of detergent base materials but without precipitating silica, even after being allowed to stand for a long period of time and without losing its thixotropic properties. This is because the silica hydrogel is rich in hydrous qualities and can contain a large amount of strong acid solution. These are important characteristics which are not observed with silica xerogel prepared by the vapour phase process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Example 1 An unwashed silica hydrogel obtained by neutralizing sodium silicate with hydrochloric acid, a silica hydrogel and a silica alumina hydrogel obtained by neutralizing sodium silicate with mineral acid and thereafter washing with water, a silica xerogel obtained by neutralizing sodium silicate with mineral acid, washing with water and 4 Example 2 Sodium silicate, silica hydrogel, silica alumina hydrogel, silica xerogel and silica gel prepared by the vapour phase process were respectively put into a porcelain ball mill without previously being changed into a colloidal solution with water, and were mixed with hydrochloric acid and water, and thereafter they were subjected to wet grinding for 1 hour to obtain a strong acid silica sol having an SiO content of 2.2 wt. percent and an HCl content of 9.0 wt. percent.

The coefficient of viscosity and storage stability were as shown in Table 2.

From Table 2, it will be observed that the strong acid silica sols obtained by wet grinding sodium silicate, silica hydrogel and silica alumina hydrogel in a hydrochloric acid solution are of the same or higher coefficient of viscosity as compared with that of the silica gel prepared by the usual vapour phase process, and are exceedingly superior in stability.

TABLE 2 Silihca E y Silica vapour Sodium Silica alumina Silica phase Name of raw material silicate hydrogel hydrogel xerogel process Water content of raw gel (percent) 880 880 4. 1 1. 8 Conditions for preparing strong acid silica sol liquid:

Constituents of grinding material:

80 183 183 23 22. 32% hydrochloric acid (g 308 281 305 281 281 Water (g.) 612 536 512 696 696. 5 Grinding time (hr.) 1 1 1 1 1 Coefiicient of viscosity (cp.). 270 290 340 120 Storage stability 1 3102 percent (27.5 wt. percent). 2 Stable more than 3 months. 8 Formed precipitate in 1 day. 4 Stable for 2 months.

Example 3 drying and a silica gel obtained by the vapour phase process were respectively put into a porcelain ball mill with water and were subjected to wet grinding at an SiO concentration of 6 wt. percent to obtain raw silica sols. The respective raw silica sols were mixed with 32% hydrochloric acid and water to prepare strongly acidic silica sols having an SiO content of 2.2 Wt. percent and an HCl content of 9.0 wt. percent. The coefiicient of viscosity and storage stability of these materials were as shown in Table 1.

As is clear from the results shown in Table 1, it can be recognized that when hydrochloric acid is added to the silica sols obtained by wet grinding silica hydrogel and silica alumina hydrogel, there can be prepared an exceedingly stable strongly acidic silica sol of the same or improved coefficient of viscosity as compared with that made of the silica gel prepared by the usual vapour phase process. Furthermore, it is recognized that, as is shown also in 'Example 4, the NaCl-containing silica hydrogel in the unwashed state can be used as a raw hydrogel.

Measurements were made in respect of the variations of the coefficient of viscosity of sols caused by variations of the silica concentration of the strongly acidic silica sols obtained in Examples 1 and 2 Within the range of from 0.5 to 5 wt. percent. The results of measurements made by using the raw silica sols disclosed in Example 1 are shown in Table 3, and the results of measurements made using the gels in Example 2 are shown in Table 4. In these tests, the HCl concentration was maintained constant at 9.0 wt. percent.

Further measurements were made in the variations of the coefiicient of viscosity caused by changing the concentration of hydrochloric acid within the range of from 3 to 20 wt. percent. The results of measurements made by using the raw silica sol liquid disclosed in Example 1 are shown in Table 5, and the results of measurements made by the use of the gels disclosed in Example 2 are shown in Table 6. In these tests, the silica concentration was maintained constant at 2.2 wt. percent.

TABLE 1 Silica gel by Unwashed Silica vapour silica Silica alumina Silica phase Name of raw material hydrogel hydrogel hydrogel xerogel process Water content oi raw gel (percent) l 87. 0 88.0 88.0 4. 1 1. 8 Conditions for preparing raw silica sol:

aw gel (g.) 460 500 500 62. 5 61 Water (g.) 540 500 500 937. 5 939 Grinding time (hr 1 1 1 1 1 Constituents for preparing strong acid silica sol:

Raw silica sol liquid 367 367 367 367 367 32% hydrochloric aci 281 281 281 281 281 a r (g.) 352 352 352 352 352 Coefficient of viscosity (cp.) 460 410 850 120 Storage stability 5 1 Dried at C. I Measured With Brookfield viscometer.

! The raw material was put into a tight stoppered SOD-ml. reagent bottle, being let stand at room temperature,

and thereaiter observation was made in sedimentation.

4 Stable more than three months. 5 Formed precipitate in one day. Stable or two months.

A tendency for the coeificient of viscosity for the re- TABLE spective raw materials to change in response to variations of silica concentration is noted as in Examples 1 and 2,

Coetficient of viscosity (cp.)

buteepecially silica hydrogeland silica alumina hydrogel Hydrochloric I I gs n c; exhibit a tendency largely to increase the viscosity. Deter- 5 t a id Unwas lll ed ST 1 sil ca ST vaplour 00110611 18, 1011 S1 108 l 103, a 111111118 1 108 p 8.58 gent base materials having various coefiic1ents of vis- (Wt percent) hydrogel hydrogel hydrogel wage, process cosity can be manufactured in the range of from 0.5 to 5 2 wt. percent silica concentration. 1, ,3 8 8 i2 1 8 Furthermore, the variation of hydrochloric acid con- 470 490 960 120 500 560 1, 070 15 120 tent does not exert a considerable influence on the coefficient of viscosity, so that strongly acidic silica sol liquids TABLE 6 containing various concentrations of hydrochloric acid can be prepared by using each of the raw materials.

Coefficient of viscosity (cp.)

Silica Hydrochloric gel by 15 acid Unwashed Silica vapour concentration silica Silica alumina Silica phase (wt. percent) hydrogel hydrogel hydrogel xerogel process 260 290 340 15 190 TABLE 3 270 290 340 15 190 270 300 350 15 100 Coefiicient of viscosity (cp.) 290 320 380 15 190 Silica Exam le 4 I n P S111 Unwashed silica The coefficient of viscosity and storage stability were concentration silica Silica alumina Silica phase (wt. percent) hydrogel hydrogel hydrogel xcrogel process evaluated when sodium chloride was added to the strong 130 160 190 80 acid silica sol obtained according to Examples 1 and 2. 240 280 47 100 The results of measurements respecting the strong acid gig gg 2 228 $3 $8 silica sol prepared by adding sodium chloride, water and 1,580 1,940 210 1, 430 32% hydrochloric acid to the raw silica sol obtained in Example 1, said strong acid silica sol having Si0 2.2 wt. percent, HCl 9.0 Wt. percent and NaCl 7.0 wt. percent,

are shown in Table 7, and the results of measurements concerning the strong silica sol prepared by adding sodium chloride, water and 32% hydrochloric acid to the raw gel which had not previously been changed into a TABLE 4 35 colloidal solution, said strong silica sol having Si0 2.2 wt. percent, 1101 9.0 wt. percent and -Na-Cl 7.0 wt. percent, are given in Table 8.

Coeflicient. of viscosity (cp.)

fi g As seen from the above-described results, when a strong Silica Silica vgpmg acid silica sol is prepared by the use of sodium silicate, concentration sqiiiurtn h sili a gna g 3 5- izgiig silica hydrogel and silica alumina hydrogel, by the addipercent) m e y y g8 g p tion of sodium chloride there can be obtained an exceedrig gg 8 ingly high viscosity of the strong acid silica sol in each 270 290 340 15 190 instance. However, in the case of silica gel prepared by 520 550 660 40 410 va our hase roces h 1,090 1,220 1,770 150 1,160 p p p s, t e above described effect 18 not manifested remarkably.

TABLE 7 Siligaa g9 Y Silica vapour Sodium Silica alumina Silica phase Name of raw material silicate hydrogel hydrogel xerogel process Constituents for preparing strong acid silica sol:

Raw silica sol liquid (g.) c c 367 367 367 367 367 Sodium chloride (g.) -c 70 70 70 70 32% hydrochloric acid (g.) 281 281 281 281 281 Water (g.) 282 282 282 282 282 Coefiicient of viscosity (cp.) 710 708 1,130 10 150 Storage stability (1) (1) 2 (a) 1 Stable more than three months. 2 Formed precipitate in one day. 5 Stable for two months.

TABLE 8 Silica gel by Silica vapour Sodium Silica alumina Silica phase Name of raw material silicate hydrogol hydrogel xerogel process Conditions for preparing strong acid silica sol liquid:

Constituents of grinding material:

Raw gel (g.) 183 183 23 22. 5 Sodium chloride (g.)... 70 70 70 70 70 32% hydrochloric acid (g.) 308 281 281 281 281 Water (g.) 542 466 466 626 626. 5 Grinding time (hr.) l 1 1 1 1 Coefficient of viscosity (cp.) 470 620 970 10 Storage stability c. (1) (1) 2) a l Stable more than 3 months. 2 Formed precipitate in 1 day. 8 Stable for 2 months.

7 Example According to the process mentioned in Example 1, there was prepared a raw silica sol (Si0 '6 wt. percent) by using silica hydrogel obtained by the steps of neutralizing sodium silicate with mineral acid and washing the same with water, and to said raw silica sol was added water, 32% hydrochloric acid and various kinds of me tallic salts to prepare a strong acid silica sol having SiO- 2.2 wt. percent, HCl 9.0 wt. percent and metallic salt 7.0 wt. percent. The coeflicient of .viscosity and storage stability of said strong acid silica sol are shown in Tab-1e 9. On the other hand, the aforesaid silica hydrogel without being changed into a colloidal solution beforehand was mixed with Water, 32% hydrochloric acid and various kinds of metallic salts thereby to prepare a strong acid silica sol according to the process mentioned in Example 2. The coefiicient of viscosity and storage stability thereof are shown in Table 10.

It will be recognized from the above-described results that a viscosity-increasing effect which salts exert towards a strong acid silica sol is manifested not only when using sodium chloride but also when using other metallic salts, thereby improving the strong acid silica sol liquid in its coefiicient of viscosity.

TABLE 9 Name of metallic salt Blank KCl CaCl MgCl A10];

Constituents for preparing strong acid silica sol:

Raw silica sol liquid (g.) 867 367 367 367 367 Metallic salt (g.) 0 70 70 70 70 32% hydrochloric acid 281 281 281 281 281 Water (g 352 282 282 282 282 Coeflicient of vis 410 486 690 675 980 Storage stability U) 1 Stable more than 3 months.

TABLE 10 Name of metallic salt Blank KCl CaCh MgCl A101 Conditions for preparing strong acid silica sol:

Constituents of grinding material:

Raw silica hydrogel (g. 183 183 183 183 183 Metallic salt (g.) 0 70 70 70 70 32% hydrochlor acid (g.) 281 281 281 281 281 Water (g.) 536 466 466 466 466 Grinding time (hr.) 1 1 l 1 l Coefiicient of viscosity (cp.) 270 385 530 570 935 Storage stability 1 Stable more than 8 months.

Example 6 According to the same process as mentioned in Examples 1 and 2, there was prepared a strong acid silica sol by using silica hydrogel obtained by the steps of neutralizing sodium silicate with mineral acid and washing the same with water and using, as the acid, sulfuric acid, nitric acid and a mixed acid of sulfuric acid and hydrochloric acid (the mixed acid of 35 wt. percent HCl and 35 wt. percent H SO The coeflicient of viscosity and storage stability of said strong acid silica sol are shown in Tables 11 and 12. As given in Tables 11 and 12, a strong acid silica sol liquid of high coeiiicient of viscosity can he prepared even by using a strong acid other than hydrochloric acid.

I 35% hydrochloric acid plus 35% sulfuric acid, 4 Stable more than 3 months.

a 35% hydrochloric acid plus 35% sulfuric acid. 4 Stable more than 3 months.

Example 7 The coefiicient of viscosity and storage stability of a strong acid silica sol liquid prepared by adding, as a surface active agent, 1.2 wt. percent of cation surface activator such as quaternary ammonium salt, etc. to (l) a strong acid silica sol liquid (coeificient of viscosity 410 cp.) prepared from the silica hydrogel in Example 1 and to (2) a strong acid silica sol liquid prepared from sodium silicate and (3) a strong acid silica sol liquid (coefficient of viscosity 340 cp.) prepared from silica alumina hydrogel in Example 2 and thereafter stirring the same, are shown in Table 13.

It is recognized from the above-mentioned results that by adding a surface active agent to a strong acid silica sol liquid there can be obtained a strong acid silica sol liquid having a superior coefi'icient of viscosity and stability.

Example -8 The coeflicient of viscosity and storage stability of a strong acid silica sol liquid obtained in case of mix grinding the respective detergent constituents such as silica, hydrochloric acid, a surface active agent (quaternary ammonium salt), sodium chloride and perfume by means of a porcelain pot mill were examined with regard to each of the silica materials. The results are shown in Table 14. The mixing proportion of the constituents is as follows:

Wt. percent Silica *1.6, 2.2 Hydrochloric acid 9.0 Sodium chloride 7.0 Quaternary ammonium salt 1.2 Perfume 0.1

Calculated in terms of anhydride.

As is clear from the above results, when a final product has been prepared by the use of sodium silicate, silica hydrogel and silica alumina hydrogel, there can be prepared the acid detergent of the same or improved stability as compared with the one prepared in case of using a silica gel prepared by the vapour phase process. It, furthermore, should be said that an important characteristic of the present invention is that the concentration of silica can be lowered by the use of sodium silicate, silica hydrogel and silica alumina hydrogel.

TABLE 14 Silica gel by Silica vapour Sodium Silica alumina Silica phase silicate hydrogel hydrogel xerogel process Silica concentration, 1.6 wt. percent:

Coeflicient of viscosity (cp.) 480 530 570 120 280 Storage stability Silica concentration, 2.2 wt. perce Coefficient of viscosity (cp.) 1, 830 2, 470 3, 100 250 430 Storage stability 1 Stable more than 5 months. 2 Separated in 1 day. 3 Separated in 1 month.

What we claim is: 1. A method of preparing a highly viscous, strongly acidic, detergent-base material, which comprises:

wet grinding a mixture consisting essentially of (1) water and (2) silica hydrogel or silica alumina hydrogel, said mixture having a pH of about 1 to about 7 and having a silica content of from about 0.5 to about 8 wt. percent, to obtain a silica hydrosol;

then mixing said hydrosol with a mineral acid selected from the group consisting of hydrochloric acid, sulfuric acid, and nitric acid and mixtures of sulfuric acid and hydrochloric acid, and controlling the water content of said hydrosol, to obtain a highly viscous, strongly acidic silica hydrosol having a silica content in the range of from 0.5 to 5.0 wt. percent and having a mineral acid content in the range of from 3.0 to 20.0 wt. percent.

2. The method of claim 1 including the step of adding to said hydrosol up to 7.0% by weight of a metallic salt selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, magnesium chloride and aluminum chloride.

3. A method of preparing a highly viscous, strongly acidic, detergent-base material, which comprises:

wet grinding a mixture consisting essentially of (1) Water plus a mineral acid selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid and mixtures of sulfuric acid and hydrochloric acid, and (2) sodium silicate, silica hydrogel or silica alumina hydrogel, said mixture having a pH of about 1 to about 7 and having a silica content of less than about 8 wt. percent, and controlling the mineral acid content and water content of the mix ture to obtain a highly viscous, strongly acidic silica hydrosol having a silica content in the range of from 0.5 and 5.0 wt. percent and having a mineral acid content in the range of from 3.0 to 20.0 wt. percent.

4. The method of claim 3 including the step of adding to said hydrosol up to 7.0% by weight of a metallic salt selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, magnesium chloride and aluminum chloride.

References Cited UNITED STATES PATENTS 2,375,738 5/1945 White 2523l3 X 2,085,129 6/1937 Stoewener 252-313 X RICHARD D. LOVERING, Primary Examiner US. Cl. X.R.

252-313 S, 317, 528, DIG. 14 

